This invention relates to doors for use in household refrigerators, and particularly to such doors that are formed of a sheet of a pre-coated metal, such as pre-painted steel for example. For many years refrigerator doors have been formed from sheets of steel which are bent into the desired box like configuration; with front, top, bottom and side walls and an open back. The corners between the top and bottom walls, on the one hand, and the side walls, on the other hand are welded together to form closed corner constructions. The welds are unsightly and rough and must be ground to a smooth surface before the door is painted. This is a messy and time consuming process. More recently some refrigerator doors have been formed of sheets of pre-painted steel. If a pre-painted sheet is welded, the paint in the area around the weld is ruined. After the sheet is folded to form the front, top, bottom and side walls; the corners between the top and bottom walls, on the one hand, and the side walls, on the other hand, are closed with fillers, such as plastic corner pieces. Such doors do not have as much strength and rigidity as welded doors. This is a particular disadvantage in large doors or in deep doors, in which numerous items and large items can be stored in shelves or containers on the inside of the door.